Tidal Power | Kaipara Harbour

An application has been made by Crest Energy to construct a marine turbine power generation using tidal power in Kaipara Harbour in northern New Zealand. The project will be made up of 200 submerged marine tidal turbines that will have a maximum generating capacity of 200MW.

It’s estimated that when the turbines are fully operational they will be capable of supplying power for up to 250,000 houses. It’s possible that the Kaipara Tidal Project could contribute 3% of New Zealand’s power supply.

At this stage the application from Crest Energy to allow it to use Kaipara Harbour for 35 years has been lodged and the company hopes that this approval will be granted some time in 2008, although environmental issues have to be cleared as well as issues with the Cultural Impact Assessment which formed part of the July 2007 application. The likelihood looks increasingly promising after New Zealand Prime Minister Helen Clark launched the New Zealand Energy Strategy (NZES) in October 2007 which includes a target to generate 90% of electricity from renewable resources by 2025.

The entrance to Kaipara Harbour is 5.6km wide and is up to 40 metres deep. The flood and ebb tides that pass through the mouth of the harbour generate currents of 2 – 3 m/sec. Crest Energy’s application to Northland Regional Council is seeking consent to install the 22m-tall turbines into the sea bed along 8km of the channel at the mouth entrance.

The proposed cost of the project was originally estimated at NZ$600 million is 2006. The initial cash requirement for Crest Energy to commence construction is estimated to be NZ$40 miilion. It is expected that the project will take 10 years to complete with revenues starting to be produced from year 3 onwards as a phased approach will be taken.

At current wholesale electricity prices, Crest Energy can expect to earn around NZ$100 million in revenue from the 200 tidal turbines.